1. Field of the Invention
The devices and processes described herein relate, in general, to dental imaging systems.
2. Description of the Related Art
Dental imaging systems are systems that obtain, manipulate, process, and electronically store and display dental image data. A Computerized Digital Radiography (CDR) system constitutes an example of dental imaging systems.
Non-CDR dental imaging systems traditionally use radiographic film to obtain and capture dental images. Non-CDR dental imaging systems can capture a number of traditional “views” of a patient's teeth and associated bony structures. Three such traditional views upon which dental professionals heavily rely are the bitewing, periapical, and occlusal views.
Unlike non-CDR systems, CDR systems utilize charge-coupled device (CCD) array sensors, rather than radiographic film, to directly obtain digital dental images. Since CDR systems allow the dental images to be captured directly to digital form, such CDR systems effect the “paperless” dental office, in that the images are stored in digital format (e.g., on CD-ROM or magnetic disk drive) rather than film. Readily available commercial embodiments of such CDR systems may be obtained from several companies, such as Shick Technologies, of Long Island, N.Y.; Trophy Radiology Inc., of Marietta, Ga.; Dexis Dental, of Palo Alto, Calif.; and Dentsply International Inc.'s Gendex Division, of Des Plaines, Ill.
CDR systems have many advantages. Examples of such advantages are that CDR systems do not require radiographic film, nor do they require the processing capabilities and darkroom capabilities necessary to develop the radiographic film into a traditional radiograph, nor do they require traditional backlit radiographic viewers. However, CDR systems are not without disadvantages.
Significant disadvantages associated with CDR systems are associated with the extremely high financial and or technical costs associated with the engineering and production of the CDR-system CCD-array sensors. Those having ordinary skill in the art will recognize that while standard digital cameras use CCD-array sensors, and the cost of such CCD-array sensors is beginning to come down with mass production, the financial and or technical costs associated with engineering and producing CDR-system CCD-array sensors are now, and are expected to remain in the future, extremely high. One reason for such high financial and technical costs is that CDR system CCD-array sensors require much, much greater pixel resolution than standard digital camera CCDs. Non-CDR radiographic film has resolution of about 14 lines/millimeter (mm). Insofar as CDR system digital images are intended to replace the non-CDR radiographic film images, every effort is made in the industry to produce CDR-system CCD-array sensors capable of capturing a digital image having resolution comparable to the non-CDR system radiographic film. At present even though the industry has expended considerable financial and technical resources, the average resolution available with CDR-system CCD-array sensors is about 8 lines/mm; thus, currently available CDR-system CCD-array sensors tend to be very expensive due to expenditures associated with past efforts to achieve the resolution of the radiographic film and continuing efforts to continue to approach the resolution of the radiographic film.
Another reason for the high financial and technical costs associated with CDR-system CCD-array sensors is that CDR system CCD-array sensors require much, much greater gray-scale resolution than standard digital camera CCDs (each CCD-array sensor pixel has a value, proportional to the amount of absorbed radiation, which is converted to a grey level). Non-CDR radiographic film, being an extremely sensitive analog recording device, tends to reproduce gray scale shading with extremely high resolution. In contrast, CCD-array sensors, being digital recording devices, must produce the gray scale in steps (e.g., 0–264 “shades” of gray), and producing CCD-array sensors capable or such gray scale resolution also tends to be very financially and/or technically expensive, for reasons similar to those associated with the high pixel resolution requirement. Yet another reason for the high financial and technical costs associated with CDR-system CCD-array sensors is that CDR-system CCD-array sensors detect X-ray frequency photons, and since the energy per photon in X-rays is substantially greater than the energy per photon of visible light, the CDR-system CCD-array sensors must be able to withstand significantly more wear and tear than the CCD-array sensors used in the standard digital camera; thus, engineering and producing such rugged CCD-array sensors also tends to be relatively expensive financially and/or technically.
A consequence of the foregoing-described cost issues related to CCD arrays utilized in the CDR systems is that CDR systems do not, in general, provide readily available digital images of occlusal views because of the financial cost and technical difficulties associated with constructing CCD-array sensors of a size necessary to capture the views. The target area of occlusal views tends to be, on average, roughly four times (4×) the target area of CDR-system CCD-array sensors currently available. Because of the foregoing-noted technical issues associated with CDR-system CCD-array sensors, increasing the size of a CCD necessary to capture an image within a larger target is not a linear operation in either financial cost or technical difficulty. Rather, doubling the size of the target area to be captured by a CDR-system CCD-array sensor could have an associated cost/technical difficulty logarithmically proportional to that associated with the smaller target area, while quadrupling the target area could have an associated cost/technical difficulty logarithmically proportional to that associated with the smaller target area. Accordingly, due to financial and/or technical difficulty issues, CDR systems do not generally provide digital images of occlusal views, since the target area of such occlusal views tends to be, on average, roughly four times (4×) the target area of CDR system CCD-array sensors currently available.
Irrespective of the foregoing-noted difficulties, as noted above, dental professionals have a longstanding and ongoing reliance on occlusal view radiographic images. As also noted above, CDR systems have significant advantages over non-CDR systems. In light of the foregoing, the inventor named herein (inventor) has posited that if a method and apparatus could be devised which would allow the production of CDR-system digital images showing views over target areas which are in the same or different orientation as currently available images, but several multiples in size the currently available CDR system digital image views (e.g., occlusal views) in such a way that the foregoing-cataloged related-art financial and technical difficulties associated with constructing CDR-system CCD-array sensors capable of capturing such increased target areas are avoided, such a method and apparatus system would be extremely advantageous. Unfortunately, no such method and apparatus currently exist within the art.